Patent Application
20130328963
The present invention relates to an inkjet printer.
There is known an inkjet printer for recording an image or the like by ejecting ink onto a recording medium such as recording paper and a resin film. In the inkjet printer, various kinds of ink are used. For example, solvent ink using an organic solvent as a primary solvent, ultraviolet curable ink, heat curable ink, and other various kinds of ink are used depending on applications. For example, JP 2006-264328 A discloses an inkjet printer using heat curable ink prepared so that fixing thereof is promoted by heat. In this apparatus, a heater is arranged above a carriage to extend along a scanning direction of the carriage.
[PTL 1] JP 2006-264328 A
The conventional technology provides a system in which heat is applied to the ink and the recording medium immediately after the ink is ejected from an ink jet head, to thereby dry the ink efficiently. In this case, the heater is arranged immediately above the ink jet head. In such a configuration, the carriage including the inkjet head is heated immediately below the heater, and hence the temperature of the ink jet head rises, resulting in ejection failure. Therefore, in the conventional technology, cooling fans are arranged in parallel to the heater, and air is blown into the carriage to cool the carriage. Further, a windshield is provided to the carriage so that the air is easily blown into the carriage. The cooling fans provided at both ends in the scanning direction of the carriage are configured so that the air flows from the inside to the outside, and thus the air flows from the center side toward both the ends. Further, JP 2006-264328 A discloses technologies for preventing temperature rise of the carriage, such as a system for cooling the carriage with cooling water and a configuration in which a heat resistant plate for reflecting light is arranged on an upper portion of the carriage.
However, there are problems in that an excessive space is necessary and cost increases in the case of using the cooling water, the heat resistant plate, and the like.
Further, the fans are mounted above the carriage in the direction toward the recording medium, and hence there is also a problem in that the air is blown also to the recording medium immediately before and after the printing and therefore the recording medium is cooled. When the outside air is actively introduced in a direction toward the carriage, the following problems arise. That is, the temperature of the recording medium is dropped, and hence the ink landing on the recording medium causes fixing failure. Further, the air is led to a nozzle surface of the ink jet head, and hence ejection failure occurs.
To cope with the above-mentioned problems, according to the present invention, there is provided an inkjet printer, including: ink to be fixed onto a recording medium, the ink being prepared so that drying thereof is promoted by heat; an ink jet head for ejecting the ink onto the recording medium; a carriage having the ink jet head mounted thereto, the carriage being configured to reciprocate in a scanning manner in a direction crossing a conveyance direction of the recording medium; a platen arranged to be opposed to a bottom surface side of the carriage, the platen being configured to hold the recording medium; and a heater arranged above the carriage, the heater being configured to heat the ink landing on the recording medium, the heater being arranged inside a casing, the inkjet printer being configured to fix the ink onto the recording medium by heating the ink immediately after landing on the recording medium, the inkjet printer further including: an exterior opening portion for air intake, which is arranged in a rear surface of the casing, and is configured to take an outside gas into the casing therethrough; an intake fan for an apparatus interior, which is provided to the exterior opening portion, and is configured to feed air into the casing; a rear surface opening portion provided at a position on the carriage, which is opposed to the exterior opening portion; an exhaust opening portion for air exhaust from inside the carriage, the exhaust opening portion being arranged to be oriented toward a downstream side of the carriage in the conveyance direction of the recording medium; an exhaust duct including a duct intake opening portion for air intake, which is provided inside the casing, the exhaust duct passing through the casing at a position on an opposite side to the recording medium across the heater, the exhaust duct further including a duct exhaust opening portion provided to the casing at a position on a delivery side of the recording medium, the duct exhaust opening portion being configured to exhaust the air toward an outside of the casing therethrough; and a duct exhaust fan provided to the duct exhaust opening portion, the duct exhaust fan being configured to discharge a gas from inside the exhaust duct to the outside.
The outside air taken into the apparatus directly enters the carriage, to thereby prevent the rise in temperature inside the carriage. The outside air that is not taken into the carriage is taken into the exhaust duct extending through the upper portion of the apparatus, and is discharged to the outside. Thus, the air at the temperature of the outside air is not led onto the recording medium, to thereby prevent the temperature drop of the ink immediately after the landing. At the same time, the amount of air that is led to the nozzle surface of the head is significantly small, to thereby prevent various problems inherent in the head, such as reduction in landing accuracy of the ink, increase of ink mist, and drying of the nozzle.
An embodiment of the present invention is described with reference to the drawings.
A platen 11 formed of a flat plate is provided to the casing at a position on the bottom surface side of the carriage 4. A recording medium 10 such as recording paper and a resin film is conveyed by a conveyance apparatus (not shown) so as to be guided onto the platen 11. The inkjet head 8 ejects the ink onto the recording medium 10 that is held on the platen 11, to thereby form an image. The platen 11 may have a suction hole to hold the recording medium 10.
Heaters 12 are mounted immediately above the carriage 4, that is, on a top surface side of the casing. Heaters 12 rapidly heat the ink ejected from the ink jet head 8. A sheathed heater, a carbon heater, or the like is used as each of the heaters 12. Considering a distance from the heaters 12 to the recording medium 10, it is preferred that the ink be heated through infrared-ray irradiation instead of heating the ink through thermal conduction. Thus, it is preferred that each of the heaters 12 be a heater that radiates a large amount of infrared rays. For example, it is preferred to use a ceramic heater, a carbon heater, and a sheathed heater subjected to surface treatment so as to facilitate emission of the infrared rays.
A given period of time is necessary from the time when the power of the heaters 12 is turned ON until the temperature thereof reaches a desired temperature. Therefore, it is necessary to turn ON the power before ejecting the ink. That is, when the apparatus is in use, the power of the heaters 12 is mostly turned ON, and the portion around the heaters 12 is heated. An opening portion 13 is formed in the front of the carriage 4, that is, on a delivery side of the recording medium 10, and the air inside the carriage is exhausted by a carriage exhaust fan 14. Thus, the air taken into the carriage 4 by the carriage intake fan 6 passes through the vicinity of the ink jet head 8 inside the carriage 4, and is exhausted toward the front of the carriage 4 by the carriage exhaust fan 14 so that the portion around the ink jet head 8 may also be set at a temperature close to the temperature of the outside air. The carriage 4 has a box-like shape with the opening portion 5 in the rear and the opening portion 13 in the front, and hence the gas inside the carriage 4 flows from the opening portion 5 in the rear to the opening portion 13 in the front.
Still further, even in a case where the carriage exhaust fan 14 is omitted as an example of improvement toward a simpler configuration, the pressure of the gas inside the carriage 4 is increased by the carriage intake fan 6, and hence the gas is exhausted through the opening portion 13 located in the front of the carriage 4. However, as compared to the case of using the carriage exhaust fan 14, the air flow rate is decreased, resulting in a small exhaust amount.
Inside the carriage 4, a carriage temperature sensor 15 is arranged at a position in the vicinity of the ink jet head 8, to thereby confirm whether or not the temperature inside the carriage 4 is a temperature appropriate to the ink jet head 8. Also inside the apparatus, an internal temperature sensor 16 is arranged at a position in the vicinity of the carriage 4, to thereby confirm whether or not the internal temperature is appropriate. An exhaust duct 17 is provided on the front side of the apparatus, and a duct exhaust fan 18 is mounted so as to take, into the exhaust duct 17, the gas that is taken into the apparatus through the intake fan 3 for an apparatus interior, which is located on the rear surface of the apparatus, and to discharge the gas thus taken in. Therefore, at a location at which the carriage 4 is not provided, the gas taken into the casing is mainly taken into the exhaust duct 17, thereby being capable of reducing the amount of the gas flowing toward the ink jet head 8, and preventing fluctuation of an ejection direction, which is caused by the air flow, and a temperature drop of the recording medium 10. A part of the exhaust duct 17 is located so as to cover an upper portion of the heaters 12, to thereby serve also as a reflection plate for the infrared rays radiated from the heaters 12. As a result, the ink may be heated more efficiently. It is preferred that the exhaust duct 17 be made of a metal to have a gloss thereon or a gloss or white layer be formed on a surface of the exhaust duct 17, to thereby increase the surface reflectance. A discharge direction of the air to be exhausted by the duct exhaust fan 18 may correspond to a conveyance direction of the recording medium 10, or may correspond to a direction toward the recording medium 10 when the drying of the ink is to be promoted. When the air is exhausted in the conveyance direction of the recording medium 10, the exhausted gas triggers the gas, which is exhausted by the carriage exhaust fan 14, to be discharged actively outside the apparatus. In order to blow the air toward the outside, the blowing direction of the gas to be exhausted by the duct exhaust fan 18 is preferred to be inclined in the delivery direction of the recording medium within a range of 0° or more and less than 90° with respect to a surface of the recording medium 10. With this configuration, the temperature management for the ink jet head 8 is facilitated, and at the same time, the air may be taken into the apparatus and exhausted outside the apparatus without causing significant turbulence of the air flow in the vicinity of the nozzle surface. As a result, the problems such as the increase of ink mist and the drying of the nozzle are prevented so that the printing stability may be enhanced.
The gas flows from the rear surface of the inkjet printer in the direction toward the front surface, thereby preventing the gas from flowing toward the ejection surface of the ink jet head 8.
The present invention is applicable to an ink jet printer.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-044295 | Mar 2011 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2011/074896 | 10/28/2011 | WO | 00 | 8/15/2013 |
